This will be a randomized, placebo-controlled, double-blind (for DHEA but no exercise) study of the independent and combined effects of DHEA and exercise training. Subjects will be 96 men and 96 women, aged 60-75 yr, who are healthy but sedentary. They wll be randomized to receive either DHEA 50 mg/d or placebo and to participate in either supervised or home exercise training programs. The home exercise program represents a placebo exercise program with respect to the variables under investigation in this study, i.e., cardiac output and VO max, nusce mass and strength, fat mass, and bone mineral denisity. The supervised exercise progrm will include both resistance and enduance training components , designed to bring about increases in muscle mass, strength, and bone mass, inprovement in cardiovascular function, and a decrease in fat mass. The goal of this research is to provide information regarding thepotential of DHEA replacement therapy in maintaining health and fuctional capacity of the elderly.